Publication Abstract

Microfibres are a prevalent form of microplastic pollution in aquatic environments, with research focussing on synthetic polymers in marine systems. Furthermore, non-synthetic microfibres, here defined as materials of natural origin, that have been manipulated or altered to fulfil applications, such as wool, cotton and rayon, have been increasingly recognised as a component of microplastic pollution. Emerging attention has also been brought to the ecological ramifications of non-synthetic microfibres and associated chemical additives. However, investigations have often underestimated microfibres due to difficulties in the collection, processing and identification of materials. This includes non-synthetics, that have also been assumed to not be of environmental concern. This systematic review aimed to collect and analyse all investigations that have observed non-synthetic microfibres in aquatic organisms. In addition, current knowledge relating to the ecological impact of non-synthetic microfibres was collated. This review demonstrates that synthetic and non-synthetic microfibres are a significant component of microplastic contamination in aquatic organisms across environments, habitats and feeding strategies, with greater contamination in freshwater environments. The ecological impacts of non-synthetic microfibres elicit similar and sometimes greater negative effects on organisms that interact with them. This review highlights the underestimation and misidentification of non-synthetics due to methodological limitations and inconsistent reporting. Here we emphasise that future research focuses on developing standardised microplastic survey methodologies that incorporate non-synthetic particles and microfibres, with greater effort placed on understanding pollution in freshwater organisms. Further exploration into the ecological impact of non-synthetics is crucial to understanding and mitigating the risks associated with these pollutants.

Daniel Jolly, Eoin O’Gorman, Dannielle Senga Green, Richard Cooper, Adil Bakir *, Trevor Tolhurst